Tag Archives: Azure IaaS

Isolated Azure VMs | New Sizes

Microsoft has announced two new IaaS VM sizes called E64i_v3 and E64is_v3 earlier today. These VM SKUs have isolated hardware and can be dedicated to a single customer.Microsoft recommends these two SKUs for workloads that needs a  a high degree of isolation from other customers for compliance and regulatory requirements.
Performance & Pricing Matters

The performance and pricing of E64i_v3 and E64is_v3 are same as their predecessors cousins E64_v3 and E64s_v3. Also the two new SKUs are available in all regions supported by E64_v3 and E64s_v3 sizes. As you may have already guessed, the simple  letter ‘i’ in the VM size name denotes that they are isolated.

Here are some facts about the new sizes.

  • E64i_v3 and E64is_v3 are hardware bound sizes unlike   E64_v3 and E64s_v3.
  • E64i_v3 and E64is_v3 operate on Intel® Xeon® Processor E5-2673 v4 2.3GHz hardware only and will be available until at least December 2021.
  • These sizes will have 12 months in advance after December 2021 to be decommissioned and after that MSFT will  offer updated isolated sizes with their next gen hardware.
  • On May 1st, 2018 these sizes will be made available as one-year Reserved VM Instances.
What are my other options?

Here is the full list of isolate VM sizes that is available in Azure Public cloud as of today.


Azure VM OS disk limitation lifted

Whenever I engage in an Azure IaaS project one of the first questions that my customers ask is why Azure VMs can’t have more than 127 GB in OS Disk? That is a very difficult moment for me when I pitch Azure as a platform to my customer so I asked myself why on earth they can’t lift the ban on OS disk?

This week I bring some good news. Now you can have OS disks up to 1 TB of size in your Azure VMs. Well probably nobody is going to need that much of beef. But the whole idea behind 127 GB cap was to discourage people from using their C:\ drive to store production workloads. Yes to stop keeping everything in one book, simple as that. This rule of thumb still remains same but keep in mind when you want to store more persistent data inside an Azure VM always use a data disk as OS disk is caching optimized for OS performance.

How do I create a 1 TB OS disk?

The answer is no you don’t. Because when you create a VM from the gallery you don’t have such an option. This limit increase applies for those VMs that you are going to migrate from on-premise environment or custom VHDs (for templates) that you upload. If you play close attention to below you can see all my VMs created from gallery/marketplace still has the 127 GB limit imposed. So basically this applies for your migration workloads.


This limit increase only applies for your own VMs. VMs used for cloud service roles such as web/worker roles still have the 127 GB limit in OS disk as these are Microsoft managed instances.

If you are planning your DR environment or production hybrid cloud with Azure VMs you no longer need to worry about the OS disk size issue as this update has already addressed that. (But it’s still 1 TB so try not to pass that limit on OS drive)